Summary: While successful immunity relies on the ability of host immune factors to rapidly recognize and respond to a variety of microbial determinants, microbial glycans often serve as the first and most important contact point with host immune factors. However, the binding specificity of most innate and adaptive immune factors toward microbial glycans remains largely unknown. Furthermore, despite the near universal use of genomic sequencing approaches to characterize microbiota, these methods largely fail to identify microbes based upon their unique glycan signatures, precluding the identification of distinct microbial strains with relevant glycan structures when using this approach. In order to effectively overcome current limitations in the study of host-microbial interactions, a platform must be developed that can be used by a wide variety of investigators to define how hosts interact with microbial glycans. Our long-term goal is to develop an integrated platform of microbial glycans and genomic sequences that can be used to define the network of innate and adaptive immune interactions with microbial glycans by a wide range of investigators. Our hypothesis is that microbial glycan arrays populated with pathogens and host microbiota coupled with corresponding genomic sequences will provide a unique and broadly useful strategy to define the specificity of host immune factors toward microbial glycans. Our hypothesis is formulated on the basis of our recent discoveries that innate and adaptive immune factors can interact with a variety of distinct microbial glycans using a platform populated with intact microbes and their corresponding microbial glycans printed in a microarray format. As microbial communities are extremely diverse, our preliminary data also demonstrate that microbes can be specifically isolated from a complex microbial mixture and that microbes and their respective glycans can be similarly printed and interrogated for host immune factor interactions. Furthermore, the genomic library generated from these isolated microbes can be successfully incorporated into traditional approaches designed to study host-microbial interactions, directly democratizing the field. In order to provide the breadth of microbial coverage needed to effectively assess host microbial interactions, we will build on these initial findings to develop an integrated set of tools that will be broadly available to the scientific community through the following specific aims: Specific Aim 1: Develop integrated microbial glycan arrays and genomic databases populated with known pathogens. Specific Aim 2: Develop integrated microbial glycan arrays and genomic databases populated with normal microbial flora highlighted by interactions with host immune factors. Given the fundamental nature of host interactions with microbial glycans and the documented success of array platforms in ?democratizing? the field of glycosciences, the integrated tools developed in this proposal will provide a wide range of investigators the opportunity to study host-microbial interactions with significant implications on fundamental and disease-related processes.